Development of in situ measurement system for welding deformation using digital cameras

Abstract A three-dimensional (3D) deformation (in plane and out of plane deformations) measurement method is developed using digital cameras, which require no special equipment. This method is a non-contact method, and it can sequentially measure over the entire photographed image. Furthermore, since image analysis is based on the technique of image matching, the method is applicable even when the deformation to be measured is large. In addition, since it is possible to use all pixels as measuring points, the number of available measuring points at one time is the same as the number of effective pixels of the camera. In this study, the proposed method is applied to the sequential measurement of displacement under strong lighting levels in arc welding. Through the comparison of the results measured by a 3D shape measurement system (LAT-3D) using a laser displacement gauge and digital caliper, the quantitative validity of the proposed method is also verified.